I welcome you to the clinic, and thank you for your participation before asking you to undress. I clear the room to offer you some privacy and return in a surgical gown. I sanitize my hands, glove up, and use stainless steel sounds to ensure we don't introduce any bacteria into your urethra. Once the sound is inserted I ask you to describe the sensations you are experiencing. When you develop an erection, and it's not just a reaction to the stimulation, I can't resist continuing to observe your pleasure.... I should probably stop, surely I have enough data... But I'm curious, and want to see it through.